It is the purpose of the present invention to generate a binary video image consisting of only black and white levels with no gray tones which will contain as much of the detail of the original video signal as is possible with a binary image.
In the binary video image generated, the surface shape characteristics such as curvature may not be apparent, but most other types of detail such as lettering, square edges, texture, etc., would not be lost, even in the presence of variable light conditions, whether it be bright light or shade.
In prior art devices with the use of a single peak detector results were obtained in the dynamic range of only 10 to 1. This occurs because the first part of the prior art peak detector is a differentiator. The amplitude of the output of a differentiator is directly proportional to both the frequency and the amplitude of the input.